Jay Fields' Thoughts: Ruby: Class Methods:

The real stumbling block is that Java class methods are totally different things from Ruby "class" methods, so different that applying Java rules of thumb to Ruby just isn't even relevant. If you can get a Java programmer to see the difference in what classes are, the class methods stumbling block vanishes. Didn't include C# because I have no experience with it, but I believe C# has an object/classes model virtually identical to Java's, so this may be equally relevant there as well. It's partly just that knowing OOP is very different from knowing Java's OOP, or Ruby's OOP. Ruby's OOP runs on a Smalltalk paradigm which is very different from Java's.